“I don’t think I was that aware really of how famous Harry was,” Nolan said on Friday (July 7). “I mean, my daughter had talked about him. My kids talked about him, but I wasn’t really that aware of it. So the truth is, I cast Harry because he fit the part wonderfully and truly earned a seat at the table.”

Rylance also learnt about the former One Direction singer via a younger relative – his 11-year-old niece – as Billboard reports.

“She was just more excited than anything I’ve ever done because I was going to be acting with Harry Styles,” Rylance said. “I went up in her estimation. I won the Harry!”

Meanwhile, Styles described his first days on the film’s set as “overwhelming”. “I’d say realizing the scale of the production was very overwhelming,” he explained. “I think whatever you imagine kind of a giant film set to be like, this was very ambitious even by those standards. You know the boats and the planes and the volume of bodies … it was pretty amazing.”

The singer also said his former bandmates are big fans of Nolan and are “excited to see” his movie debut.

Dunkirk, which also stars Kenneth Branagh, Cillian Murphy and Tom Hardy, will be released in cinemas on July 20.